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Related papers: Optimal control of molecular spin qudits

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Optimal control theory provides a framework for numerical discovery of device controls that implement quantum logic gates, but common objective functions used for optimization often assign arbitrarily high costs to otherwise useful…

Quantum Physics · Physics 2021-10-07 Paul Kairys , Travis S. Humble

We report on the experimental investigation of an individual pseudomolecule using trapped ions with adjustable magnetically induced J-type coupling between spin states. Resonances of individual spins are well separated and are addressed…

Quantum Physics · Physics 2012-08-13 A. Khromova , Ch. Piltz , B. Scharfenberger , T. F. Gloger , M. Johanning , A. F. Varón , Ch. Wunderlich

High-fidelity gate implementation requires sophisticated control pulses that steer the quantum system to undergo the desired transformation. Quantum Optimal Control allows to derive these control pulses in an open-loop fashion based on…

The ability to control spins in semiconductors is important in a variety of fields including spintronics and quantum information processing. Due to the potentially fast dephasing times of spins in the solid state [1-3], spin control…

Optimal control theory is a powerful tool for solving control problems in quantum mechanics, ranging from the control of chemical reactions to the implementation of gates in a quantum computer. Gradient-based optimization methods are able…

Quantum Physics · Physics 2015-10-06 Michael H. Goerz , K. Birgitta Whaley , Christiane P. Koch

We present an efficient strategy for controlling a vast range of non-integrable quantum many body one-dimensional systems that can be merged with state-of-the-art tensor network simulation methods like the density Matrix Renormalization…

Quantum Physics · Physics 2015-03-13 Patrick Doria , Tommaso Calarco , Simone Montangero

We have developed semiconductor point contact devices in which nuclear spins in a nanoscale region are coherently controlled by all-electrical methods. Different from the standard nuclear-magnetic resonance technique, the longitudinal…

Quantum Physics · Physics 2009-11-13 Y. Hirayama , A. Miranowicz , T. Ota , G. Yusa , K. Muraki , S. K. Ozdemir , N. Imoto

A gate sequence of single-qubit transformations may be condensed into a single microwave pulse that maps a qubit from an initialized state directly into the desired state of the composite transformation. Here, machine learning is used to…

Quantum Physics · Physics 2025-07-18 Jaden Nola , Uriah Sanchez , Anusha Krishna Murthy , Elizabeth Behrman , James Steck

Defects in solid state materials provide an ideal, robust platform for quantum sensing. To deliver maximum sensitivity, a large ensemble of non-interacting defects hosting coherent quantum states are required. Control of such an ensemble is…

The presence of decoherence in quantum computers necessitates the suppression of noise. Dynamically corrected gates via specially designed control pulses offer a path forward, but hardware-specific experimental constraints can cause…

Quantum Physics · Physics 2022-05-31 Utkan Güngördü , J. P. Kestner

We propose a two-qubit collisional phase gate that can be implemented with available atom chip technology, and present a detailed theoretical analysis of its performance. The gate is based on earlier phase gate schemes, but uses a qubit…

We use quantum optimal control theory algorithms to design external electric fields that drive the coupled spin and orbital dynamics of an electron in a double quantum dot, subject to the spin-orbit interaction and Zeeman magnetic fields.…

Mesoscale and Nanoscale Physics · Physics 2016-02-17 J. A. Budagosky , D. V. Khomitsky , E. Ya. Sherman , Alberto Castro

Using micromagnets to enable electron spin manipulation in silicon qubits has emerged as a very popular method, enabling single-qubit gate fidelities larger than 99:9%. However, these micromagnets also apply stray magnetic field gradients…

Mesoscale and Nanoscale Physics · Physics 2021-09-15 N. I. Dumoulin Stuyck , F. A. Mohiyaddin , R. Li , M. Heyns , B. Govoreanu , I. P. Radu

High fidelity quantum control over qubits is of crucial importance for realistic quantum computing, and it turns to be more challenging when there are inevitable interactions among qubits. By employing a bandselective shaped pulse, we…

Quantum state control is a fundamental tool for quantum technologies. In this work, we propose and analyze the use of quantum optimal control to exploit the dipolar interaction of ultracold atoms on a lattice ring, focusing on the…

Combining the features of molecular wires and femtosecond laser pulses gives the unique opportunity to optically switch electron currents in molecular devices with very high speed. Based on a weak-coupling approximation between wire and…

Mesoscale and Nanoscale Physics · Physics 2007-08-22 GuangQi Li , Sven Welack , Michael Schreiber , Ulrich Kleinekathoefer

In this paper, we present a unified computational method based on pseudospectral approximations for the design of optimal pulse sequences in open quantum systems. The proposed method transforms the problem of optimal pulse design, which is…

Chemical Physics · Physics 2009-08-17 Jr-Shin Li , Justin Ruths , Dionisis Stefanatos

Inhomogeneity, in its many forms, appears frequently in practical physical systems. Readily apparent in quantum systems, inhomogeneity is caused by hardware imperfections, measurement inaccuracies, and environmental variations, and…

Optimization and Control · Mathematics 2011-02-21 Justin Ruths , Jr-Shin Li

Fewer-qubit quantum logic gate, serving as a basic unit for constructing universal multiqubit gates, has been widely applied in quantum computing and quantum information. However, traditional constructions for fewer-qubit gates often…

Quantum Physics · Physics 2021-12-20 Rui Li , Shurui Li , Dongmin Yu , Jing Qian , Weiping Zhang

Quantum computation places very stringent demands on gate fidelities, and experimental implementations require both the controls and the resultant dynamics to conform to hardware-specific constraints. Superconducting qubits present the…

Quantum Physics · Physics 2018-04-11 Shai Machnes , Elie Assémat , David J. Tannor , Frank K. Wilhelm